Deep ocean floor show basaltic oceanic crust and overlying sediment which become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge. Second,the rock making up the ocean floor is considerably younger than the

continent. This confirms that older ocean crust has been reabsorbed in

General term for an underwater mountain system that consists of various mountain ranges (chains), typically having a valley known as a rift running along its spine, formed by plate tectonics.

Basaltic Volcanism

Volcanoes are generally found where tectonic plates are diverging or converging. Mid-Atlantic Ridge, Pacific Ring of Fire

Covergent Boundaries

Boundary where two plates are forced into eachother

3 Types of Convergent Boundaries

Oceanic to Continental-oceanic plate is subducted due to the fact that it is more dense, which can cause volcanos and mountain building

Oceanic to Oceanic-subduction, causing underwater volcanoes to form

Continental to Continental-two continental plates collide, neither subducts into the mantle, the

crust is thickened, and mountain ranges are formed from the thickening

and uplift

Subduction

The process by which an oceanic plate is driven beneath another plate into the mantle along a convergent boundary

Accretionary Wedge

formed from sediments that are accreted onto the non-subducting tectonic plate at a convergent plate boundary. Most of the material in the accretionary wedge consists of marine sediments scraped off from the downgoing slab of oceanic crust

Island Arc

A type of archipelago composed of a chain of volcanoes which alignment is arc-shaped, and which are situated parallel and close to a boundary between two converging tectonic plates

Back Arc Basin

Geologic features, submarine basins associated with island arcs and subduction zones, result from tensional forces caused by oceanic trench rollback and the collapse of the edge of the continent

Fore Arc Basin

A depression in the sea floor located between an accretionary wedge and a

volcanic arc in a subduction zone, and lined with trapped sediment.

Andestic Volcanism

In an Andestic magma contains 52–63% silica, the lava is of intermediate composition.These "andesitic" volcanoes generally only occur above subduction zones. Andesitic lava is typically formed at convergent boundary margins of tectonic plates

Obduction

Obduction occurs where a fragment of continental crust is caught in a subduction zone with resulting overthrusting of oceanic mafic and ultramafic rocks from the mantle onto the continental crust creating an ophiolite.

Ophiolite

a section of the Earth's oceanic crust and

the underlying upper mantle that has been uplifted and exposed above sea

level and placed on the continental crust

Trench

A deep long depression in the sea floor making the surfaceof a subduction zone

Docking

Beginning of an accretion event which is a process by which material is added to a tectonic plate or a landmass. This material may be sediment, volcanic arcs, seamounts or other igneous features

Sutres

A suture is structural geology in a major fault zone through an orogen or mountain range.

Accreted Terrain

A portion of a plate added to a larger block of crust

Micro Plate

Any small lithospheric plate.

Suspect Terrane

Lithology, age, fossils, and paleomagnetic orientation of a suspect terrane may differ from its host continent.